Condition.cpp revision 263363 
1//===-- Condition.cpp -------------------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include <errno.h>
11
12#include "lldb/Host/Condition.h"
13#include "lldb/Host/TimeValue.h"
14
15
16using namespace lldb_private;
17
18#ifndef _WIN32
19
20//----------------------------------------------------------------------
21// Default constructor
22//
23// The default constructor will initialize a new pthread condition
24// and maintain the condition in the object state.
25//----------------------------------------------------------------------
26Condition::Condition () :
27    m_condition()
28{
29    ::pthread_cond_init (&m_condition, NULL);
30}
31
32//----------------------------------------------------------------------
33// Destructor
34//
35// Destroys the pthread condition that the object owns.
36//----------------------------------------------------------------------
37Condition::~Condition ()
38{
39    ::pthread_cond_destroy (&m_condition);
40}
41
42//----------------------------------------------------------------------
43// Unblock all threads waiting for a condition variable
44//----------------------------------------------------------------------
45int
46Condition::Broadcast ()
47{
48    return ::pthread_cond_broadcast (&m_condition);
49}
50
51//----------------------------------------------------------------------
52// Unblocks one thread waiting for the condition variable
53//----------------------------------------------------------------------
54int
55Condition::Signal ()
56{
57    return ::pthread_cond_signal (&m_condition);
58}
59
60/* convert struct timeval to ms(milliseconds) */
61static unsigned long int tv2ms(struct timeval a) {
62    return ((a.tv_sec * 1000) + (a.tv_usec / 1000));
63}
64
65//----------------------------------------------------------------------
66// The Wait() function atomically blocks the current thread
67// waiting on the owned condition variable, and unblocks the mutex
68// specified by "mutex".  The waiting thread unblocks only after
69// another thread calls Signal(), or Broadcast() with the same
70// condition variable, or if "abstime" is valid (non-NULL) this
71// function will return when the system time reaches the time
72// specified in "abstime". If "abstime" is NULL this function will
73// wait for an infinite amount of time for the condition variable
74// to be signaled or broadcasted.
75//
76// The current thread re-acquires the lock on "mutex".
77//----------------------------------------------------------------------
78int
79Condition::Wait (Mutex &mutex, const TimeValue *abstime, bool *timed_out)
80{
81    int err = 0;
82    do
83    {
84        if (abstime && abstime->IsValid())
85        {
86            struct timespec abstime_ts = abstime->GetAsTimeSpec();
87            err = ::pthread_cond_timedwait (&m_condition, mutex.GetMutex(), &abstime_ts);
88        }
89        else
90            err = ::pthread_cond_wait (&m_condition, mutex.GetMutex());
91    } while (err == EINTR);
92
93    if (timed_out != NULL)
94    {
95        if (err == ETIMEDOUT)
96            *timed_out = true;
97        else
98            *timed_out = false;
99    }
100
101    return err;
102}
103
104#endif
105
106//----------------------------------------------------------------------
107// Get accessor to the pthread condition object
108//----------------------------------------------------------------------
109lldb::condition_t *
110Condition::GetCondition()
111{
112    return &m_condition;
113}
114